The global growth of Pentecostal movements during the course of the twentieth century has been widely documented although, to date, there has been little written on their developing ecclesiology. After making the case for a concrete rather than idealised approach to ecclesiology, this book describes and analyses the transitions that have framed the ways in which Australian Pentecostals have understood church life and mission. From a loosely knit faith missions movement, to congregational free church structures, to the so-called apostolic models of mega-churches, Australian pentecostalism stands as a microcosmos of ecclesial developments that have occurred throughout the world. This book, therefore, provides a means of reflecting upon what has been gained and lost in the process of ecclesiological change.